HTTP 416 Range Not Satisfiable (Requested Range Not Satisfiable)
Updated Free mock REST & WebSocket APIs
HTTP 416 Range Not Satisfiable — The byte range requested in the Range header is outside the size of the resource.
- Class
- 4xx Client Error
- Defined in
- RFC 9110 §15.5.17
- Official
- Yes (IANA registry)
- Cacheable by default
- No (unless Cache-Control/Expires say so)
- Safe to retry
- Not without changing the request
Try it: get a real 416 response
Our test endpoint answers every request with 416 Range Not Satisfiable.
curl -i https://mockfox.dev/api/status/416Use it in tests, health-check monitors or to see how your client handles a 416. Add ?delay=2000 to slow it down.
What does HTTP 416 mean?
Sent when a client asks for Range: bytes=5000- of a 4000-byte file, typically because a download manager resumes against a file that changed or shrank. The response should include Content-Range: bytes */4000 with the real size. Deleting the partial download and starting over fixes it.
Also known as: Requested Range Not Satisfiable.
How to fix 416
- Visitors: Reload the page, check the address for typos, and clear the site's cookies. If it persists, the site owner needs to fix it.
- Developers: Read the response body and server logs for details, fix the request (method, headers, body, credentials) and return a clear error message to clients.
Example 416 response
HTTP/1.1 416 Range Not Satisfiable
Content-Range: bytes */4000
Content-Type: application/json
{"status":416,"error":"Range Not Satisfiable"}4xx Client Error: The request contains an error or can't be fulfilled — fix the request before retrying. See the full list of HTTP status codes.
Related status codes
- 206 Partial ContentThe server is returning only the byte range the client asked for in its Range header.
- 200 OKThe request succeeded and the response contains the result.
- 412 Precondition FailedA condition in the request headers (If-Match, If-Unmodified-Since…) evaluated to false.
Related tools
Frequently asked questions
What does HTTP 416 Range Not Satisfiable mean?
The byte range requested in the Range header is outside the size of the resource.
Is 416 a client or a server error?
416 is a 4xx code, so it signals a problem with the request (as seen by the server). Retrying the identical request usually gives the same result.
Where is 416 defined?
In RFC 9110 §15.5.17. It's listed in the IANA HTTP Status Code Registry.
How can I test how my app handles a 416?
Call https://mockfox.dev/api/status/416 — it responds with 416 to any method, with CORS enabled. Add ?delay=2000 to simulate a slow response.